Using QProcess on 7zip and connecting Slots does not provide output to Textbox Widget

[kayot]

The issue was -bs, I thought it defaulted to o1, e2, p1 but that isn't the case when it's ran from a C++ instance. I had to tell it to put progress or -bsp# to 1. To direct quote the manual for 7zip 18.06 (x64);

-bs (Set output stream for output/error/progress line) switch

Syntax
-bs{o|e|p}{0|1|2}
{id} Stream Type
o standard output messages
e error messages
p progress information
{N} Stream Destination
0 disable stream
1 redirect to stdout stream
2 redirect to stderr stream
Default values: o1, e2, p1.

Examples
7z t a.7z -bse1 > messages.txt
tests a.7z archive and sends error messages to stdout that is redirected to messages.txt

7z a -si -so -bsp2 -txz -an < file.tar > file.tar.xz
compresses file.tar (from stdin) to file.tar.xz (stdout stream) and shows progress information in stderr stream that can be seen at console window.

Commands that can be used with this switch
a (Add), d (Delete), h (Hash), l (List), e (Extract), u (Update), x (Extract with full paths)

I was able to use the Windows Subsystem for Linux to speed testing up in this case. When I sent stdout to a text file with > FileName.txt and used less, I saw that without -bsp1 it wasn't outputting anything. When the process finished I had the same thing I had in my Qt application. Adding -bsp1 to the 7zip command;

if (ArchiveType == "7z")
        {
            Args << "-t7z";
            Args << "-bsp1"; //<== Added Here
            Args << "-m0=LZMA2:d512m:fb273";
            Args << "-mx9";
            Args << "-myx=9";
            Args << "-mtc=off";
            Args << "-mtm=off";
        }
        else
        {
            Args << "-tzip";
            Args << "-bsp1"; //<== And Here
            Args << "-mx";
            Args << "-mtc=off";
        }

if (ArchiveType == "7z")
        {
            Args << "-t7z";
            Args << "-bsp1"; //<== Added Here
            Args << "-m0=LZMA2:d512m:fb273";
            Args << "-mx9";
            Args << "-myx=9";
            Args << "-mtc=off";
            Args << "-mtm=off";
        }
        else
        {
            Args << "-tzip";
            Args << "-bsp1"; //<== And Here
            Args << "-mx";
            Args << "-mtc=off";
        }

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I got full feedback. I can also send the output to a different channel, -bsp2 which will send it to the error channel for easier parsing. I can use the output channel for final details and each line is absolutely positioned.

In short, my connect was working fine. It was 7zip that was giving me trouble.